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simplify some code to just reuse a setcc if we can instead of 

going through the CSE maps to get it.

llvm-svn: 122196
This commit is contained in:
Chris Lattner 2010-12-19 21:23:48 +00:00
parent 21dcac2128
commit 6dddab2ffe
1 changed files with 16 additions and 11 deletions
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27
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -7018,8 +7018,7 @@ SDValue X86TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
// Lower (X & (1 << N)) == 0 to BT(X, N).
// Lower ((X >>u N) & 1) != 0 to BT(X, N).
// Lower ((X >>s N) & 1) != 0 to BT(X, N).
if (Op0.getOpcode() == ISD::AND &&
Op0.hasOneUse() &&
if (Op0.getOpcode() == ISD::AND && Op0.hasOneUse() &&
Op1.getOpcode() == ISD::Constant &&
cast<ConstantSDNode>(Op1)->isNullValue() &&
(CC == ISD::SETEQ || CC == ISD::SETNE)) {
@ -7028,19 +7027,25 @@ SDValue X86TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
return NewSetCC;
}
// Look for "(setcc) == / != 1" to avoid unnecessary setcc.
if (Op0.getOpcode() == X86ISD::SETCC &&
Op1.getOpcode() == ISD::Constant &&
// Look for X == 0, X == 1, X != 0, or X != 1. We can simplify some forms of
// these.
if (Op1.getOpcode() == ISD::Constant &&
(cast<ConstantSDNode>(Op1)->getZExtValue() == 1 ||
cast<ConstantSDNode>(Op1)->isNullValue()) &&
(CC == ISD::SETEQ || CC == ISD::SETNE)) {
X86::CondCode CCode = (X86::CondCode)Op0.getConstantOperandVal(0);
bool Invert = (CC == ISD::SETNE) ^
cast<ConstantSDNode>(Op1)->isNullValue();
if (Invert)
// If the input is a setcc, then reuse the input setcc or use a new one with
// the inverted condition.
if (Op0.getOpcode() == X86ISD::SETCC) {
X86::CondCode CCode = (X86::CondCode)Op0.getConstantOperandVal(0);
bool Invert = (CC == ISD::SETNE) ^
cast<ConstantSDNode>(Op1)->isNullValue();
if (!Invert) return Op0;
CCode = X86::GetOppositeBranchCondition(CCode);
return DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
DAG.getConstant(CCode, MVT::i8), Op0.getOperand(1));
return DAG.getNode(X86ISD::SETCC, dl, MVT::i8,
DAG.getConstant(CCode, MVT::i8), Op0.getOperand(1));
}
}
bool isFP = Op1.getValueType().isFloatingPoint();